#include <stdio.h>
#include <math.h>
#define NUM 320
int number[NUM];
main()
{
    int i, j, count=0;
    printf ("There are follwing primes sequences in first row:\n");
    for (j=0, i=3; i<=1993; i+=2)
      if (fflag(i)) number[j++]=i;
    for (j--; number[j]>1898; j--)
    {
        for (i=0; number[j]-number[i]>1898; i++);
        if (number[j]-number[i]==1898)
         printf(" (%d). %3d,.....,%d\n", ++count, number[i], number[j]);
    }
}
fflag(i)
 int i;
 {
    int j;
    if (i<=1) return(0);
    if (i==2) return(1);
    if(! (i%2)) return(0);
    for (j=3; j<=(int)( sqrt((double)i)+1 ); j+=2)
      if ( ! (i%j)) return(0);
    return(1);
 }